Most work concentrated upon leishmaniasis, schistosomiasis, and filariasis, although a variety of other parasitic infections were seen. Follow-up on the cases with diffuse cutaneous leishmaniasis (DCL) was continued. In contrast to the DCL patients, those with positive leishmanin skin tests in the same endemic area exhibited blastogenic responses to leishmanial antigens. One new case and a drug-treated relapse were treated with local heat at the NIH. Immunologic modulation which depresses both immediate and cell-mediated reactions in chronic schistosomiasis was reversed in patients after treatment of their infections. The development of assays for antibodies to a variety of parasite antigens promises to be useful for both diagnosis and better understanding of pathophysiology of certain parasitic infections. It is now possible to measure parasite-specific IgE to schistosome and filarial antigens, including different stages of the parasites. Also, the proportion of parasite specific IgE and IgG can be estimated. IgE antibodies were found to show greater specificity than IgG to different species of filarial parasites in sera of infected patients. An ELISA test, using cultured larvae as antigen, was developed for serodiagnosis of human strongyloides infection. Results of treatment of S. mekongi infections with Praziquantel were excellent with only mild side effects.